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In page Masamune:

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Masamune studied under Shintōgo Kunimitsu and made blades in suguha (straight temper line) but he made notare hamon, where the finish on the leading edge of blade slowly undulates where it was quenched. There are also some blades with ko-midare (small irregularities), a style which appears to have been copied from the Old Bizen and Hōki Province styles. His works are well-characterized by striking chikei (dark lines following the grain pattern in the steel above the hamon), kinsuji (lightning shaped lines of nie) and nie (crystals of martensite embedded in a pearlite matrix).